1. Field of the Invention
The present invention relates to a disk drive such as a hard disk drive (HDD). In particular, the invention relates to a recording disk drive comprising a recording disk and a ramp member located at a location outside the recording disk.
2. Description of the Prior Art
A head actuator is incorporated in a hard disk drive, HDD, for example. The head actuator includes a head actuator member swinging around a support shaft so as to follow a predetermined path. The support shaft is fixed to the base with a screw. The support shaft is likewise coupled to the cover with a screw. A ramp member is disposed at a position outside the magnetic recording disk on the predetermined path of the head actuator member. When the magnetic recording disk stands still, the tip end of the head actuator member is received on the ramp member. A head slider is supported on the tip end of the head actuator member.
A latch mechanism is also incorporated in the hard disk drive. The latch mechanism includes a lever supported on a first shaft for swinging movement. A weight is connected to the lever. The weight is thus supported on the first shaft for swinging movement. A swinging member is related to the lever. The swinging member is supported on a second shaft for swinging movement. The swinging member is designed to contact first or second operating spot defined at the tip end of the lever. The swinging movement of the lever around the first shaft causes the swinging movement of the swinging member around the second shaft.
When the magnetic recording disk stands still, impact acting on the enclosure of the hard disk drive induces inertial force driving the head actuator member around the support shaft. The weight is also forced to move around the first shaft based on inertial force. The lever thus swings. The swinging movement of the lever causes the swinging member to get into the predetermined path of the head actuator member. The swinging member thus serves to restrict the swinging movement of the head actuator member. Contact can be avoided between the head slider and the surface of the magnetic recording disk.
The lever is located at a position between the first and second operating spots within a space between the swinging member and the cover in the hard disk drive. The first and second operating spots are distanced from the first shaft by first and second distances, respectively. The weight is distanced from the first shaft by a third distance shorter than the first and second distances. A larger displacement can thus be obtained at the tip end of the lever. When impact is applied to the enclosure of the hard disk drive, the tip end of the lever is supposed to move in parallel with the axis of the first shaft by a larger amount. The lever thus collides against the cover. The contact causes noise.
In this case, if the lever successively collides against the cover, the cover suffers from not only noise but also vibration. Since the cover is coupled to the support shaft with a screw, the vibration of the cover is transmitted to the head actuator member through the screw. The vibration of the head actuator member leads to a deteriorated accuracy in positioning the head slider relative to the magnetic recording disk. The head slider sometimes fails to read or write information with a higher accuracy.
In addition, the lever and the first shaft are supposed to wear out due to the contact between the lever and the cover. Dust is thus generated based on the wear. The generated dust brings disadvantages to the flight of the head slider.